Ruger® 10/22® rifles manufactured by Sturm, Ruger & Co., Inc. of Southport, Conn. are one of the most successful recreational shooting rifles in history. The rifle's popularity stems from its origins as one of the first modern rifles chambered in .22 caliber that featured a quality design suitable for use by adults. Its easy handling characteristics, negligible recoil, and inexpensive ammunition make it ideal for young or inexperienced shooters. However, the rifle is also widely used by small game hunters and those who want an inexpensive rifle firing inexpensive ammunition for target and plinking use. These characteristics also make it useful as a training rifle for police and military applications. A wide range of after-market modifications are available to improve the rifle's performance, augment the rifle's appearance, and increase its magazine capacity.
The rifle's design employs an integrated modular subassembly approach depicted in FIG. 1. The modular construction of the components means the average person can easily replace any part of the gun using only a screwdriver, a hex key, and simple punches.
The trigger guard assembly 122 of the 10/22® rifle 100 contains the entire firing mechanism, which features a short-throw, high-speed swinging hammer 158 for rapid lock time. The trigger guard assembly is held together by trigger guard assembly pins 148 inserted in trigger guard assembly pin holes 124. The one-piece .22 Long Rifle (LR) receiver 136 is milled from a solid block of cast aluminum and is drilled and tapped for a tip-off scope mount adaptor supplied with the rifle. The bolt assembly 126 reciprocates within the receiver. The motion of the bolt assembly 126 is controlled by a cocking handle 130 mounted on a guide rod 132 and a recoil stop pin 142 attached to the receiver. The magazine 116 is a compact rotary 10-shot unit.
The barrel 102 uses a unique attachment technique where the barrel is screwed rather than pinned into the frame. The barrel tenon 104 is not threaded, but attachment of the barrel to the receiver involves two barrel retainer screws 106 and a barrel retainer 108 that is received by a slot in the underside of the barrel. The forward portion of the barrel is secured to the stock assembly 118 by a barrel band 112 that is tightened by a barrel band screw 114. A takedown screw 120 further secures the barrel within the stock assembly. The upper portion of the barrel is left exposed by the stock assembly. This construction makes removal and replacement of the barrel, which would otherwise require a gunsmith's work with most other rifles, much easier.
The rifle is available in a wide variety of configurations, including multiple barrel lengths. A shorter stock is used with the shortest barrel. Otherwise, longer barrels protrude farther from the stock than shorter barrels do. A different receiver and magazine are required for use in the .22 magnum version of the rifle because the magnum cartridge is longer and has a larger case diameter than the standard Long Rifle cartridge.
In order to maximize the rifle's utility as a training weapon for users of the AR-15 rifle platform, it is desirable to modify a standard 10/22® rifle to closely resemble the appearance and geometry of an AR-15 while continuing to use standard 10/22® rifle internal components. Although many customizations of the 10/22® rifle exist, they do not feature a receiver that covers the top portion of the barrel or fully floats the forward portion of the barrel within the receiver as an AR-15 rifle's upper receiver may. Furthermore, longer barrels are typically allowed to protrude farther from the stock because it is prohibitively expensive to make a custom stock length for each barrel length. This leaves a lengthy exposed portion of barrel between the end of the stock and the beginning of a suppressor screwed onto the end of the barrel, which is cosmetically unappealing to the shooter.
Upper receivers made from aluminum extruded in a closed-box profile are known. One such upper receiver is featured in the Magpul Masada™ Adaptive Combat Weapon System designed by Magpul Military Industries of Erie, Colo. This upper receiver is shown in U.S. Pat. No. D590,473 to Fitzpatrick et al. The upper receiver has a continuous military specification top rail milled into its top and receives a barrel trunnion. The barrel trunnion acts as part of a quickly changeable barrel system that is described in detail in the United States Patent Application 2008/0168695 of Nakayama. A separate free float hand guard must be attached to the trunnion to effectively extend the length of the upper receiver to cover the rear portion of the barrel and to provide mounting points and/or integrated rails on the sides and bottom of the firearm. Two lengths of hand guard are available to adjust how much of the barrel protrudes from the hand guard.
The Masada™ upper receiver suffers the disadvantage of requiring a magazine well that is integral to the trigger pack housing rather than to the upper receiver. Furthermore, the upper receiver requires use of a separate hand guard that is attached to the trunnion in order to cover the barrel. This means that the trunnion cannot merely be repositioned within the upper receiver to accommodate a magnum load. Instead, an entirely new upper receiver design would be required. Finally, the Masada™ Adaptive Combat Weapon System requires relatively expensive M16 barrels, magazines, and ammunition instead of the much cheaper components and ammunition used with the 10/22® rifle.
Therefore, a need exists for a new and improved rifle upper receiver with integral magazine well that receives a magazine within the upper receiver. In this regard, the various embodiments of the present invention substantially fulfill at least some of these needs. In this respect, the rifle upper receiver with integral magazine well according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of receiving a magazine within the upper receiver.